n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 6 |
3 | 16 |
4 | 81 |
5 | 301 |
6 | 1451 |
7 | 6231 |
8 | 29891 |
9 | 137731 |
10 | 666976 |
11 | 3193026 |
12 | 15658831 |
13 | 76719891 |
14 | 380788006 |
15 | 1894818776 |
16 | 9502977851 |
17 | 47822585931 |
18 | 241944876266 |
19 | 1228151169656 |
20 | 6258922649451 |
21 | 31992657321551 |
22 | 164040821525031 |
[1,1,6,16,81,301,1451,6231,29891,137731,666976, 3193026,15658831,76719891,380788006,1894818776, 9502977851,47822585931,241944876266,1228151169656, 6258922649451,31992657321551,164040821525031] |